The Bel Curve
by cynically quixotic
Summary: "He wasn't sure he wanted an insane best friend who stabbed and insulted him on a daily basis. And was very very pretty and very very touchy-feely." In which Fran questions his life choices and his math tutor, and not much studying gets done. Fran/Fem!Bel


_Flick._ "Bel-senpai."

_Flick._ "What?"

"Could you stop doing that?" _Flick._

"_Ushishishi._ No." Belphegor tore another strip of paper from her notebook and scrunched it into a tiny ball, ready to take aim. She was about to fire when Fran's hand shot out and grabbed her wrist, forcing her to cease and desist.

"Bel-senpai, what are you doing in my room?" The blonde flicked Fran directly on the forehead, making him release her while she continued to sprawl herself out across his bed like a contented cat.

"Don't try to restrain the Princess, Froggy. I'm only here because stupid Jill brought her weird friends home and I didn't want to have to see their ugly faces."

"You lead a very deprived social life, senpai," said Fran, rubbing his forehead. He idly noted the way her movements twisted her striped purple dress, pulling the neckline lower and wrapping it closer around her body. Then he mentally slapped himself. _Bad Fran, bad._

"Didn't the long-haired shark say he'd kick you out of his class if you didn't finish your peer-tutoring programme?"

"Not in so many words. That's just the official version. What he really said was _'VOOOOOII!'_"

"So you're officially supposed to be here to tutor me." Fran folded his arms and leaned against the headboard, his eyes sliding shut; it wasn't like they were getting any studying done anyway. That and it really was _very_ distracting, the way her belt cinched in her waist _just so_...

"_Ushishishi._ That too."

"So what are you doing in my room?"

"Flicking paper at your head." Fran fixed her with a blank stare.

"Are you an idiot?" Belphegor slid a silver knife out of her belt loop and stabbed Fran's shoulder in one seamless motion. He pulled the knife out of the padding he wore for this very purpose and bent it effortlessly, his actions weary and suggestive of routine.

"That hurts, Bel-senpai." She pouted, and Fran tried not to think that it actually made her look _cute_. "The Princess will keep doing it until the Froggy bleeds." Nope, not cute at all.

"I thought princesses were supposed to behave with charm and decorum," Fran pointed out. "Didn't you ever read _The Princess Diaries_? Oh, wait, that's assuming you _can_ read."

"The Princess doesn't need to read stupid books to get better grades than you in math," Bel scoffed, idly playing with another of her limitless knives. Fran had no idea where she kept them all. He wasn't sure he wanted to know. Although there was probably a reason she always wore such high boots. No, it wasn't that he spent too much time eyeing up her legs. Probably.

"Better by half a grade, and not better in much else," he said instead. It was true that his senpai got better grades (in _one_ subject, thank you), but what did everyone expect? She was older by two years and had been in this... _unique_ school system since she was eight, while Fran had only moved here a year ago at the age of fourteen. It had been something of a culture shock to walk into the principal's office and find him bending the music teacher over his desk. Fran had seriously considered eating _signorina_ Bianchi's cooking to be rid of the images, but decided he didn't want that to be the last thing he saw.

Fran didn't consider the day he met Belphegor di Ripper to be the worst day of his life. No, it was every day _afterward_ that she made hell. In hindsight, he should have run away screaming (or not, because screaming wasn't really his thing). Instead, he'd asked her in all sincerity "What's it like to have hair-blindness? I've never had it before, but it must be terrible." He'd immediately regretted ever approaching the blonde demon when she whipped a silver knife out of fuck knows where and stabbed him in the upper arm.

"_Ushishishi._" Her creepy laugh had haunted him for days (and nights, and every other time) afterwards, and then she'd given him that detestable nickname-

"Oi, Froggy."

Just because his hair and eyes were green. For a self-proclaimed genius, the so-called Princess couldn't be that smart if she didn't know that frogs didn't have hair. Or that most Italian people didn't speak Japanese.

* * *

><p><em>"I am Her Royal Highness, the <em>Principessa _Belphegor di Ripper," she announced grandly after she'd finished stabbing him (for now). "You may address me as 'Your Highness'."_

_"There's no way in hell." By this point Fran was pretty sure he'd been born without a survival instinct, because it was hardly wise to piss off the rich girl with knife skills and bodyguards - not that she needed the latter._

_"The Princess is feeling magnanimous today. She supposes not everyone is worthy of speaking her name on a daily basis." The blonde frowned in thought, then suddenly lit up and clapped her hands._

_"You will call me Bel-senpai."_

_Fran said the first thing that came to mind._

_"You are _such _a weeaboo." Yup, definitely zero survival instinct. He'd have to get that fixed someday - that is, if he lived that long. But for now, at least he was getting pretty good exercise dodging the sudden influx of knives._

* * *

><p>"Froggy?"<p>

At least her sister hadn't decided to bother him too. Luckily for Fran, the twins led very separate lives. Rasiel had somehow managed to get in with their marshmallow-munching music-teacher-groping principal, and spent most of her time together with his posse. She seemed to be concentrating her energies on harassing Iris and Bluebell instead; the three females of Principal Gesso's inner circle were always at loggerheads.

"_Ushishishi._ Semi-cute kouhai, are you still there?"

He didn't think he could handle both the di Ripper girls. One was difficult enough, although somehow he didn't think Bel-senpai and Jill-senpai were that much alike. There was simply no mistaking Belphegor, and it wasn't just because of her springier hair. Maybe it was because he hung around her so much (read: she stalked him). Oddly enough, they'd become best friends (sort of, he still wasn't quite sure) over the year, although he wasn't sure he wanted a best friend who insulted him and stabbed him and had no sense of personal space. And was very very pretty and very very touchy-feely.

Suddenly Fran's vision was obscured by a tempest of springy blonde hair. He snapped to attention as the tempest shifted a fraction closer. He stared at where Belphegor's eyes should be and briefly considered making a run for it, but it was too late, for he was trapped between his senpai and the headboard. Fran tried to look elsewhere, but the only other thing in view at the moment was her bare shoulder, which he _really_ didn't want to look at... maybe.

Every sense was suddenly heightened. Fran wondered if this was what Byakuran had meant when he'd talked about 'Hyper Awareness'. Either way, he was aware that she was straddling his lap, her chest flush with his, her hands braced against the headboard on either side of his head. He could smell lavender and spice and something that was so uniquely _Bel_, could feel her breath against his lips, their noses almost touching. At this distance, he fancied he could almost make out the shape of her eyes through the blonde bangs.

Her head shifted to the side, and now he had a perfect view of her smooth, pale shoulder, leading up to the curve of her neck. Her breath tickled his ear as she cooed.

"Silly Froggy, don't space out like that."

"Senpai?" _Finally_ she moved away from him, draping herself over the edge of the bed again, and Fran released the breath he didn't know he'd been holding. _Stupid teenage hormones._ He didn't want to look at her like that. She was an older woman, completely insane, and a princess to boot. She was... Fran decided not to go in that direction. If he did, he just might find that there really was nothing stopping him.

_Falling for your best friend... how clichéd._

Belphegor yawned and stretched, cat-like, arching her back slowly. Fran tried, he really did, but he couldn't keep himself from tracing the outline of her profile with his eyes. She caught his eye and flashed her signature grin, and he flushed, embarrassed at having been caught ogling. But she was scooting closer to him now, nuzzling into his side and wrapping her arms around his waist.

"Silly Froggy," she repeated, sounding almost _affectionate_. "The Princess was getting worried when you didn't answer her."

"... Really." It wasn't a question.

"_Ushishishi._" When had her laugh stopped being disturbing? Now he couldn't imagine _not_ hearing it everyday. "The Princess thought you'd died or something." Way to ruin the moment. Part of him was grateful. But she was getting too close again, like she always did. He should have gotten used to it by now. _Should_ have.

"The only one allowed to kill you is me," she continued. Ah, that was the Bel-senpai he knew and lov-had a very complicated like-hate relationship with. No, _friendship._ Not relationship.

"What makes you think I'll let you kill me, Bel-senpai?"

"That's how we work," she hummed, as if she wasn't planning the murder of her best friend. "The only one allowed to touch you is me. And the only one who can touch me is you." Fran tried not to let his mind wander over the implications of that sentence and failed miserably.

"What if I kill you first?"

"You could," she acknowledged, running her hidden eyes appreciatively over his deceptively skinny physique. Then she was in his face _for the third time that day_, snuggling against his side and absently running a knife harmlessly over his skin. Fran shivered in spite of himself, feeling goosebumps break out where the cool metal ghosted over his flesh. _Of all the women in the world, I had to fall for the psychopath with a knife kink._

"But you won't," Bel continued, grinning up at him. "Because you like me too much."

"No, no," Fran tried to ignore the way his heart was thumping. "I'm just biding my time. See, I'm actually an assassin sent by the gay shark to kill you, because you didn't do your homework last week. Or the week before that, or the week before _that_-"

"_Ushishishi._ Silly Froggy." She seemed to enjoy calling him that today. Why was she still here? Mukuro was due home soon, and if he saw them like this, curled up together with legs tangled in the sheets, there'd be hell to pay, clothes or no clothes. He was dangerously overprotective when it came to his his little brother.

"Bel-senpai. You still haven't tutored me yet." Belphegor made a small whine of protest from her spot at his side, and the sound turned into delicious vibrations against his hip. Fran poked her shoulder.

"Bel-senpai." She huffed and sat up, removing her arms from around his waist. "Give me your hands," she instructed.

"No chance. You're probably going to cut them off." She would, too.

"I'll cut them off if you don't."

"See, senpai, there's the difference between execution and suicide."

"I'll cut out your tongue, too."

"... I rather like my tongue." Bel just threw back her head and laughed, leaving Fran to wonder for the millionth time that day just why he was friends with this maniac.

"I wonder..." she mused when she'd finally stopped laughing.

"Wonder wh-_mmpf!_" Belphegor effectively silenced him by pressing her warm lips to his. _God my ohhh._

He should have been freaking out. He should have pushed her off. Instead all he could focus on was that yes, her lips _were_ as soft as he'd always imagined. She coaxed his mouth open, her tongue darting in to stroke playfully at his own. It was weird and kind of gross at first, but Fran prided himself on being a fast learner. In everything but math, of course.

* * *

><p>It is a little-known fact that humans need oxygen to survive. After days, or hours, or possibly only six minutes, they broke apart. Oddly enough, her hands had threaded their way into his hair, while his were placed firmly on her hips. A streak of pride darted through Fran when he noticed she was nearly as breathless as him, her hair even wilder than usual and her cheeks and lips flushed pink. Little did he know he looked even worse. Ignorance is bliss, after all.<p>

Belphegor licked her lips, frowning thoughtfully. _Shit._ If she said this had all been a mistake-

"I rather like your tongue, too," she stated matter-of-factly. Fran just blinked at her. _Oh._

What were you supposed to say when your best friend who you were kinda, sorta, maybe in love with had just taken your first kiss and stuck her tongue in your mouth?

"Why did you ask for my hands, Bel-senpai?" There. Safer territory.

"_Ushishishi._ I was going to show you my variation of the bell curve," she snickered at the look of horrified realisation on his face.

"But," she continued, "this way is much better." She perched herself in his lap again, practically _purring_ in his ear. "Remember, no one else is allowed to have you but me."

It was a mark of how far they'd come in one year that Fran wasn't the least bit weirded out by that statement. "I guess I can live with that," he agreed, running his hands over her sides. He was going to make some completely stupid clichéd speech, but she kissed him again before he could get another word out. Which was just as well.

* * *

><p>"Your awesome, wonderful, loving brother is back, Little One! With a guest!"<p>

"I don't think he's here-"

The door flew open. "Oh. Um..."

"_Kufufufu._ Little One-"

"Mukuro-sama, why don't we just..."

Nagi pried Mukuro away from the door and shut it carefully, averting her eyes apologetically as she did so. Neither Fran nor Bel noticed. Mukuro could go to hell six times over for all they cared.


End file.
